Prior art methods and devices for providing alarms or alert signals to indicate the occurrence of electrical failure of electronic equipment include methods and devices that produce an audible alarm, such as a local alarm, in response to the detection of failure conditions or the failed state of one or more electronic devices or assemblies including semiconductors, transistors, capacitors, diodes, and other similar components. In particular, audible alarms are often used in monitoring methods and devices to alert operators of the electrical failure of devices or assemblies associated with power converters, uninterruptible power supplies and other power electronics used with IT and telecommunications equipment. Many of such alarms elicit relatively loud noises in response to detected failures.
In addition, failure noise produced by an electronic device or assembly as a result of catastrophic failure or the presence of failure conditions can be relatively loud. For instance, failure of a device such as an integrated gate bipolar transistor (IGBT) would elicit a particularly loud noise if the transistor operates from a high voltage bus having relatively high levels of stored electrical energy. Failure noise is often exceedingly loud and is typically not intentionally used as an audible alarm to alert operators of failed conditions. Loud failure noise, along with the consequent smoke emissions produced from failed devices and assemblies, can cause operators and other persons in, for instance, equipment rooms or data centers to become startled, as well as can prompt unnecessary evacuations of the premises in locations that enforce strict fire codes. In these cases, the magnitude of the failure noise and/or the observable smoke may not represent the extent of actual hazards or conditions the electrical failures pose.
Electronic detection schemes are used to help to detect failure conditions and to prevent catastrophic failure of devices and assemblies of electronic equipment that include electronic monitoring and sensing circuits. Such electronic circuits are configured to monitor and/or to measure electrical current, drive signals from drive/control circuits and/or voltages across corresponding devices and assemblies in order to identify conditions for failure and to prevent catastrophic failure of devices and assemblies, to thereby manage failure noise and smoke emissions. For instance, a detection scheme of monitoring electrical signals and/or monitoring power drive signals would detect failure conditions associated with a device or assembly and would cause, for instance, a power converter to shut down and discontinue electrical power to a device in response to the detected conditions. The power shut down prevents the catastrophic failure of the device and thereby prevents failure noise and smoke emissions. In another similar instance, a scheme of monitoring drive signals and voltages across corresponding devices or assemblies would determine whether the voltage to individual devices or assemblies corresponds to the signals driving the device or assembly. Such a scheme would shut down a power converter to avoid device or assembly failure and to thereby prevent failure noise and smoke emissions. Further, electrical means, such as fuses, may be incorporated in a series with devices and assemblies to help to minimize or prevent catastrophic damage to devices or assemblies and, as a consequence, to help to minimize or prevent failure noise and smoke emissions.
Other methods to achieve smokeless and soundless detection of electrical failure include the process of potting, which involves containing devices and assemblies within potting material. The potting material helps to create a barrier around the devices and assemblies to limit or prevent sound and smoke emissions produced as a result of failed devices and assemblies.
The known devices and methods mentioned above have various disadvantages. Devices and methods that produce audible alarms that sound locally in response to the detection of failure conditions or states may be unnecessarily loud or excessive and do not prevent smoke emissions.
With respect to monitoring and sensing schemes, due to the nature of the detection circuits involved, such schemes are susceptible to false tripping of detection circuits and introducing false detections, creating false indications of electrical failure, unnecessary power shut down and erroneous perceptions of hazardous conditions. Electronic monitoring and sensing schemes also do not eliminate failure noise under all types of failure conditions. In addition, such schemes can be ineffective if the underlying cause of an electrical failure is within the drive/control circuit of devices or assemblies. Furthermore, if such schemes require certain electronic components, such as current sensors, then detection schemes of this type can be relatively expensive to implement.
In addition, electronic detection schemes may not entirely prevent smoke emissions into an equipment room or data center produced as a result of failure conditions or the catastrophic failure of devices or assemblies. As mentioned, in locations enforcing strict fire codes, or having a heightened sensitivity toward any volume of observable smoke, such schemes do not accomplish smokeless failure detection and are ineffective as smoke barriers.
Further, procedures such as potting are relatively expensive and do not permit servicing of potted devices and assemblies. Also, design changes to electronic devices or assemblies, and in particular to such components as printed circuit boards, that are required to achieve soundless and smokeless electronic detection of failure conditions, may be significant and costly, as well as ineffective for all electrical conditions.
Thus, as an alternative to at least electronic monitoring and sensing schemes as a means for managing and/or preventing the production of noise and smoke as a result of electrical failure of devices and assemblies that overcomes the disadvantages of the prior art and achieves smokeless and noiseless detection of electrical failure is desirable.